The present invention relates to a synchronous electric motor.
More specifically, the subject of the invention is a single-phase synchronous electric motor comprising:
a rotor or inductor with permanent magnets, with at least one pair of poles, PA1 a stator or armature having a winding wound around a magnetic circuit, PA1 position-detecting means associated with the rotor for providing driving signals in dependence on the angular position of the rotor, and PA1 a driver circuit connected to the detecting means and to the stator winding and having a pair of terminals for connection to an alternating voltage supply, the driver circuit being arranged to control the flow of current in the stator winding in dependence on the signals supplied by the position-detecting means.
Synchronous motors of this type are characterized in that, during steady-state operation, the angular velocity .omega. (in revolutions/minute) is related to the frequency f of the alternating supply voltage (in Hz) and to the number p of pairs of poles by the known equation: EQU .omega.=f.multidot.60/p
Thus, for example, a single-phase synchronous motor with two poles (p=1) supplied with a 50 Hz alternating voltage rotates, during steady-state operation, at an angular velocity .omega.=3000 revolutions/minute.
A synchronous electric motor with 4 poles (p=2), also supplied with a 50 Hz alternating voltage, rotates, during steady-state operation, at an angular velocity of 1500 revolutions/minute.